I recently purchased the Yamaha RX-V2300 receiver.

The owner's manual states that DPLII takes a 2 channel source and creates 5 (or 6) full range channels. Nothing is mentioned about LFE.

As an experiment I set all my speakers to "large" and set the Bass/LFE to "sub". In this configuration, the sub would only turn on if there is an LFE channel.

So I put on a DVD which was Dolby Surround and selected DPLII movie mode. The sub did not turn on.

As soon as I changed any of my speakers (center, rear) to "small" the sub immediately kicked in (because rear and center bass below 90hz was being rerouted to the sub).

This appears to confirm that DPLII does not create an LFE channel.

Is this a correct assumption or was there an oversight on Yamaha's part?

[Chuck Kent]

No, from my understanding, it doesn't. Since DPL II is a matrixed derived surround format (from 2 channels) there would be no separate LFE component. But the DPL II specs do require proper bass management. (IOW, if any of the speakers are small, their bass is redirected to the mains or sub as appropriate.)

Take a look at this Dolby link for some info overload...
http://www.dolby.com/tech/l.wh.0007.PLIIops.html

Chuck:

Thanks for the reply. It confirmed what I thought.

My receiver's bass management works in all modes. If any speakers are set to small, the bass below 90hz is redirected to the sub.

[Phil Iturralde]

Quote:

... owner's manual states that DPLII takes a 2 channel source and creates 5 (or 6) full range channels. Nothing is mentioned about LFE. ...

This appears to confirm that DPLII does not create an LFE channel.

Is this a correct assumption or was there an oversight on Yamaha's part?

Adding to Chuck's post & link, ...

FYI: The following is also from Dolby's - "Dolby Digital"- What is the LFE channel? website ...

Quote:

The LFE channel as originally devise for 70 mm movie productions to deliver a separate bass signal to one or more additional subwoofers placed behind the movie screen.

To maintain full compatibility with existing theatres, the Dolby Digital film* format includes a separate LFE channel. When movies formatted for the consumer use Dolby Digital, the same tracks as originally produced are usually used, including the LFE track if available.

*Dolby Digital was first introduced to moviegoers in 1992 with Batman Returns.

So, Yamaha and other DD/DTS 5.1 / 6.1 AV Receivers for that matter, are correctly handling the bass-management based on the sound format.

Glossary:

Quote:

Dolby Pro-Logic II (Also known as DPL II)
A newly developed sound processing format from Dolby, which is a competing sound system to DTS Neo:6. DPL II takes lower quality recordings in matrixed stereo (such as analogue TV broadcasts or VHS video recordings) and generates five or six channels of sound for 5.1 and 6.1 systems respectively.

DPL II can also extrapolate a rear centre channel from 5.1 material.

Phil

[Andres Munoz]

So what's the answer Phil???????

Boy, you love to quote from other websites don't you? :wink:

[John Kotches]

Andres,

You answered the question for yourself....

DPL-2 doesn't generate an LFE channel.

When setting to small, it is Bass Management, not DPL-2 which creates the subwoofer output.

Bass Management and LFE are often confused.

Regards,

[Andres Munoz]

Quote:

Andres,
You answered the question for yourself....

I did? How did I do that?

[John Kotches]

Andres,

Sorry, I got the attributions wrong.

Regards,